I2C (Inter-Integrated Circuit) is a simple, bidirectional, two-wire serial bus protocol designed for communication between integrated circuits (ICs) on a single printed circuit board (PCB). Originally developed by Philips Semiconductors (now NXP), it is widely used for short-distance, on-board data transfer.
Key Technical Characteristics:
- Synchronous Communication: Uses a shared clock line to synchronize data transfer.
- Two-Wire Interface: Consists of a Serial Data Line (SDA) and a Serial Clock Line (SCL).
- Master-Slave Architecture: A master device (typically a microcontroller) initiates communication and generates the clock signal. Multiple slave devices, such as sensors or memory chips, can be connected to the same bus using unique 7-bit or 10-bit addresses.
- Space Efficiency: The shared bus architecture minimizes pin count and board space requirements, making it ideal for compact electronic designs.
Relevance to Power Supplies
While I2C is an internal board-level protocol, its principles form the physical layer for PMBus (Power Management Bus) and SMBus (System Management Bus). These protocols define specific command sets for monitoring and controlling power supplies.
For example, PMBus (Power Management Bus) and SMBus (System Management Bus) are protocols that are built on top of the I2C physical layer, defining specific command sets for controlling and monitoring power supplies and other system components. Therefore, while a user might control a power supply via USB or LAN, that external command is often translated by the main processor inside the unit into I2C or PMBus commands to control the actual power conversion ICs.